Piston-valve for steam-engines.



R. WOLF.

PISTON VALVE FOR STEAM ENGINES.

APPLIOATION FILED MAY 16, 1912.

1,092,967. Patented Apr. 14, 1914. F191]. I

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t d d J? 19 a m 36' m d r L 4" 4 S p L v W TTNTTED STATES PATEN T @FFTSE RUDD-LIE WOLF, OF MAGDEBURG-BUCKAU, GERMANY.

PISTON -V'ALVE FOR STEAM-ENGINES.

To all whom it may concern Be it known that I, RUDoLr VOLT, manufacturer, a citizen of the German Empire, residing at MagdeburgBuckau, Germany, have invented certain new and useful Im' provements in Piston-Valves for Steam-Engines, of which the following is a specification.

My invention relates to improvements in piston valves for steam engines of the compound type, and more particularly to piston valves of that type in which a common piston valve is provided between steam cylinders of higher and lower pressures for si multaneously controlling the exhaust from the cylinder of higher pressure and the steam admission to the cylinder of lower pressure, and which for this purpose is provided about its circumference with suitable steam ports and laps. And the object of the improvements is to reduce the number of the packings between the piston valve and the cylindrical valve casing inclosing the same and also the size of the cylinder ports.

With this object in view my invention consists in constructing the piston valve with a shell which provides a channel or passage cooperating with subsidiary port-s formed at the end of the lining of the steam chest. Thereby I am able to dispense with two or more of the admission ports to the cylinder of lower pressure.

In the accompanying drawing, Figure 1 is a longitudinal sectional view showing the valve members in their middle position, all ports being closed; and Fig. 2 is a similar view showing the valve adjusted for the admission of steam to one of the low pressure cylinder.

Referring to the example illustrated in the drawing, between the cylinder Y of higher pressure and the cylinder Z of lower pressure a steam chest X is located which is provided at opposite ends with linings (Z, (Z each formed with suitable slots 0 registering with the exhaust ports T from the cylinder Y of higher pressure and with slots d registering with the steam admission ports S to the cylinder Z of lower pressure. Furthermore the linings are formed at their inner ends with notches b. l/Vithin the linings (Z piston valves is are mounted for reciprocation, which control with their outer laps e the exhaust from the cylinder of higher pressure and with slots f the admis- Specification of Letters Patent.

Application filed May 16, 1912.

Patented Apr. ML, 1914:. Serial No. 697,657.

sion to the cylinder Z of lower pressure. Furthermore the said valves are formed with outer annular chambers m which are so arranged, that communication is established between the ports S and the notches I) when the slots f register with the ports S.

The operation of the lide valve will readily be understood from its description. When the outer laps 6 open the ports 0 and the slots f register with the ports (Z, the slide valve will be in such position that said ports 03 are also in communication with the notches b by means of the annular chamber m, so that the steam from the cylinder of higher pressure flows to port S of the cylinder Z through the slots f as well as through the notches b. In this Way the contacting area of the valve members is reduced materially as compared with the usual gratepiston-valves employed in this type of engine.

With this invention, it will be observed that the stroke of the valve is reduced to a minimum and further that it is possible to make the inlet port d of maximum area; a further advantage is that the distance be tween the two ports T and S is reduced to a minimum.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is In combination, a high pressure cylinder, a low pressure cylinder, an intermediate cylindrical valve casing having ports communicating with the aforesaid cylinders, cylindrical linings fixed in said valve casing and having ports coinciding with the aforesaid ports, each of said linings being provided wit-h supplemental ports Z), and a valve consisting of two cylindrical members each being provided with main ports and also with the annular supplemental ports adapted to put said supplemental ports in the lining into communication with the inlet ports in the low pressure cylinder at the same time the main port is in communication therewith.

In testimony whereof I hereunto aiiix my signature in presence of two witnesses.

RUDOLF WOLF.

iVit-nesses GUSTAV KnAsPnn, O'r'ro VON SZCZOPANSKI.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. O." 

